1. Field of the Invention
The invention relates in general to a backlight module, and more particularly to a backlight module having a fixing structure.
2. Description of the Related Art
Referring to FIG. 1A, a flexible printed circuit board of a conventional backlight module disposed at a frame is shown. The backlight module 100 includes several light sources 110, a frame 130, a light guide plate 150 and a flexible printed circuit board 170. The light guide plate 150 is disposed in the frame 130, and the light sources 110 are disposed on the flexible printed circuit board 170. The flexible printed circuit board 170 is bent to be disposed on two sides of the frame 130.
Referring to FIG. 1B, a cross-sectional view of the flexible printed circuit board in FIG. 1A bent and disposed on the two sides of the frame is shown. A two-sided tape 160 is disposed between the flexible printed circuit board 170 and the frame 130 so as to fix the bent flexible printed circuit board 170 on the frame 130. Therefore, the flexible printed circuit board 170 is fixed on the frame 130, and the light sources 110 are positioned at a side of the light guide plate to radiate light into the light guide plate 150. However, as indicated in FIG. 1A and FIG. 1B, the frame 130 has only a limited area on which the two-sided tape 160 (denoted by sloped lines) can be disposed. As the two-sided tape 160 can not provide enough adhesiveness, the flexible printed circuit board 170 may easily rise up due to its bounceback. Moreover, although the flexible printed circuit board 170 with a high level of hardness may reduce the possibility of the bounceback, it is not easy to bend the flexible printed circuit board 170 into the shape shown in FIG. 1B.
Referring to FIG. 1C, the flexible printed circuit board in FIG. 1B rising up due to the bend is shown. When the flexible printed circuit board 170 rises up, the light sources 110 disposed on the flexible printed circuit board 170 can not precisely radiate the light into the light guide plate 150. Thus, the light is likely to gather at a part of a display panel (not illustrated) near the light sources 110, so that the light emitting efficiency and uniformity of the backlight module 100 are decreased. Therefore, how to reduce the occurrence of the bouceback of the bent flexible printed circuit board so as to avoid the light emitting efficiency and uniformity of the backlight module being affected has become an imminent issue to be resolved.